CTCSS on VHF Marine Channels

[pb_lonny]

Is the use of CTCSS tones common on Marine frequencies? I have always had mine programmed as plain FM, with not CTCSS search. Recently I reprogrammed my BCD160DN and set these to CTCSS search, I have now logged a few different tones on a few channels. Why would they do this?

 

[mmckenna]

Not very common here in the USA. But I have seen it used. It needs to be very carefully implemented by someone who understands the rules for the country it's used in.

 

[pb_lonny]

Thank you, I guess if a channel is used by a specific company it makes sense, but it "breaks" the whole point of having access to common channels.

 

[mmckenna]

Thank you, I guess if a channel is used by a specific company it makes sense, but it "breaks" the whole point of having access to common channels.

Exactly.

Where I've seen it used is in specific industrial applications. Not sure it makes a whole lot of sense, but I guess it did to someone.

I've run across scramblers being used, also, mostly by fishing fleets to obscure locations.

 

[pb_lonny]

I've run across scramblers being used, also, mostly by fishing fleets to obscure locations.

I wonder if they have setup CTCSS thinking it works like this, if I can't hear them, they can't hear me

 

[mmckenna]

I wonder if they have setup CTCSS thinking it works like this, if I can't hear them, they can't hear me

Not sure about other countries, but here in the US, most purpose built VHF marine radios won't do CTCSS. Where I've seen CTCSS used, it's usually LMR radios that have FCC Part 80 approval, and the average user would have to spend extra money on the radio, cable and programming software to use it. Usually (not always) that indicates some level of understanding on how radios work, but as we see on this site, that's not always a guarantee.

 

[ecps92]

Not very common here in the USA. But I have seen it used. It needs to be very carefully implemented by someone who understands the rules for the country it's used in.

Also the scanner could be falsing based on the Voice and/or Ignition noises

 

[mmckenna]

Also the scanner could be falsing based on the Voice and/or Ignition noises

No, I've actually seen it used/programmed into LMR radios that have Part 80 and used in the marine industry.

 

[ecps92]

No, I've actually seen it used/programmed into LMR radios that have Part 80 and used in the marine industry.

Same, I was only also suggesting that I have also seen the PL show on my scanners due to Ignition/Engine/Power as well as voice influction

 

[KC2zZe]

I've also seen CTCSS tones programmed for use on marine band channels. The configuration of this fleet was - the vessels would transmit a specific tone / monitor in carrier squelch; the shore station that the vessels were transmitting to didn't want to be bothered hearing every Tom, Dick, and Harry using the channel, so they had their base radio set to break squelch only when they were being hailed by a vessel from their fleet, while transmitting in CSQ.

 

[jeepsandradios]

I've also seen CTCSS tones programmed for use on marine band channels. The configuration of this fleet was - the vessels would transmit a specific tone / monitor in carrier squelch; the shore station that the vessels were transmitting to didn't want to be bothered hearing every Tom, Dick, and Harry using the channel, so they had their base radio set to break squelch only when they were being hailed by a vessel from their fleet, while transmitting in CSQ.

Exact scenario I used at our FD. Our base had 3 channels in in for water rescues but all had PL on RX. Our rescue boat had PL enabled and the station could hear them and click on monitor during a rescue to monitor if needed. Our base did not TX anyway so it was more for situational awareness but in CSQ mode it was chatter all saturday afternoon.